Most contentious may be recommendation that the eavesdropping agency halt collection of the phone call records, known as “metadata.”

WASHINGTON—A White House-appointed panel on Wednesday proposed curbs on some key National Security Agency surveillance operations, recommending limits on a program to collect records of billions of telephone calls and new tests before Washington spies on foreign leaders.

Among the panel’s proposals, made in the wake of revelations by former NSA contractor Edward Snowden, the most contentious may be its recommendation that the eavesdropping agency halt collection of the phone call records, known as “metadata.”

Instead, it said, those records should be held by telecommunications providers or a private third party. In a further limitation, the U.S. government would need an order from the Foreign Intelligence Surveillance Court to search the data.

“We don’t see the need for the government to be retaining that data,” said Richard Clarke, a member of the panel and a former White House counterterrorism adviser.

Across U.S. surveillance programs more broadly, “we tend to believe there should be further judicial oversight than there has been,” Clarke said.

It remains to be seen, however, how many of the panel’s 46 recommendations will be accepted by President Barack Obama and the U.S. Congress. The panel’s five members met with Obama at the White House on Wednesday.

NSA officials have staunchly defended the bulk metadata program, saying it is essential to “connect the dots” between terrorist plotters overseas and co-conspirators inside the United States.

“There is no other way that we know of to connect the dots,” Gen. Keith Alexander, NSA’s director, told a Senate committee last week. “Given that the threat is growing, I believe that is an unacceptable risk to our country.”

Michael Morell, a former deputy CIA director who is on the White House review panel, said its members do not believe that its proposals for change “in any way undermine the capabilities of the U.S. intelligence community to collect the information it needs to collect to keep this country safe.”

In another major recommendation, the panel proposed five tests it said should be met before Washington conducts surveillance against foreign leaders.

Revelations in documents provided by Snowden that the United States spied on German Chancellor Angela Merkel and Brazilian President Dilma Rousseff have enraged those countries’ citizens.

Before spying on foreign leaders, the panel said, U.S. leaders should determine whether such surveillance is merited by “significant threats” to national security, and whether the nation involved is one “whose leaders we should accord a high degree of respect and deference.”

U.S. leaders also should determine whether there is reason to believe the foreign leader has been duplicitous, whether there are other ways to obtain the necessary information, and weigh the negative effects if the surveillance becomes public, the panel said.

It said the U.S. government should explore agreements on spying practices “with a small number of closely allied governments.”

Obama said earlier this month in a television interview that he would be “proposing some self-restraint on the NSA” in reforms that the White House has said will be announced in January.